Why one entity is a List Object? There are many such cases. They are in one level/one region/province.
CityData[{"Anqing", "Anhui", "China"}]
(* Entity["City", {"Anqing", "Anhui", "China"}] *)
CityData[{"Bangbu", "Anhui", "China"}]
(* {Entity["City", {"Bengbu", "Anhui", "China"}]} *)